Apparatus for cooling particles

ABSTRACT

Apparatus for cooling heated pieces of matter and particularly calcined lime pebbles or particles in which cooling air is introduced under positive pressure into a downwardly moving mass of particles which is adjustable for uniform cooling throughout. This is accomplished by providing air inlets adjustably positionable horizontally within the bed, dependent upon the horizontal corss-sectional shape of the bed and the pattern of particle size distribution therein. Uniformity of cooling is further promoted by positioning each air inlet along a line which coincidently divides its section of bed symmetrically into like horizontal cross-sectional shapes as well as like patterns of particle size distribution.

I United States Patent [1 1 [111 3,731,398 Niems 1 ay 8, 1973 [54] APPARATUS FOR COOLING Primary ExaminerKenneth W. Sprague PARTICLES Attorney-Charles F. Schroeder [76] Inventor: llzelllhfiigaszflm Brassie, Floss- [57] ABSTRACT Apparatus for cooling heated pieces of matter and [22] Flled May 1971 particularly calcined lime pebbles or particles in which [21] Appl. No.: 141,667 cooling air is introduced under positive pressure into a downwardly moving mass of particles which is adjustable for uniform cooling throughout. This is accomplished by providing air inlets adjustably positionable horizontally within the bed, dependent upon the horizontal corss-sectional shape of the bed and the pattern of particle size distribution therein. Uniformity of cooling is further promoted by positioning each air inlet along a line which coincidently divides its section of bed symmetrically into like horizontal cross-sectional shapes as well as like patterns of particle size distribution.

20 Claims, 7 Drawing Figures 52 vs. Cl ..34/1 69, 4 32/7 [5 1] Int. Cl. ..F27b 7/00 [58] Field of Search ..263/32; 34/169 [56] References Cited UNITED STATES PATENTS 2,970,828 2/1961 3,063,647 11/1962 3,578,297 5/l97l Niems ..263/32 ffl PATENTEDHAY 819B 3.731.398

SHEET 1 BF 2 INVENTOR. [5 M5445 WHY MM PATENTED 8975 3.731.398

SHEET 2 OF 2 5? Fig-.

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; Q- mzm firm/may 1 APPARATUS FOR COOLING PARTICLES BACKGROUND OF THE INVENTION This invention is directed to a method and apparatus for air cooling high temperature masses of particles continuously discharged from pyroprocessing apparatus, the particles here being exemplified by calcined lime pebbles such as are produced from a limestone calcining operation in a kiln. The invention is not limited to cooling of lime pebbles alone, however, since it may be applied to cooling other heated pieces of matter such as dead burned dolomite, cement, expanded shale and the like. The term particles as used herein refers to the many forms of such material including large and small pieces, pebbles, granules, broken solids, fragments, clinkers, etc. In this regard, lime particles cooled in the apparatus herein described may, for example, range in the size from dust less than 60 mesh, to l to 2 rinches pebbles or larger.

Calcining of lime is typically accomplished in a high temperature kiln such as a generally horizontal rotary kiln heated by oneor more burners, in rotary hearth type furnaces, and other types of kilns, including those of the shaft type. It is customary to subject the material being processed to flame temperatures in the order of 2,800 F. to modify the physical and chemical properties of the limestone charge. The hot lime exiting from the calcining zone is then deposited on top of a generally vertical cooling bed through which cooling air is passed in counterflow to reduce the temperature of the lime to a level that permits subsequent conveying, storage and shipment within a reasonable space and a reasonably short time period, and to return the sensible heat in the hot lime to the process in the form of preheated air for combustion.

FIELD OF THE INVENTION The mass of heated pieces of lime of such a cooling bed is contained in a hopper system in which-the mass moves gradually and continuously downwardly under the influence of gravity at a rate determined by the rate of removal of the lime from the base of the hoppers.

. The lime is received directly and continuously from the kiln and as it moves downwardly in the bed is inventoried for a period typically in the order of from threefourths to l A hours to provide the necessary time for heat transfer from the lime to the air. The cooling air is introduced into the downwardly moving mass of particles at an intermediate region between the top and discharge of the cooler to effect countertlow cooling without excessive pressure drop.

To promote maximum efficiency in the overall system incorporating the kiln and the cooling unit, the heat abstracted from the lime by the cooling air is returned to the combustion process as preheated air for combustion and, where applicable, to the drying of fuel for the combustion process.

PRIOR ART When heated particles such as calcined lime particles are fed centrally to a bed in a hopper, it is known that the fine particles of the mass tend to segregate toward the center of the bed. That is, the center of the bed in plan will have a higher percentage of fines than any other section. of the bed. Further the bed surface will exhibit a peak under the discharge, with the surface declining in all directions from this peak in a degree dependent on the natural angle of repose of the material. In the case of pebbled lime this angle would vary from 30 to 40 from the horizontal. Thus when cooling air is passed vertically through the bed, a lesser degree of cooling occurs in the central region because of its higher resistance to air flow than in the outer regions. Likewise when the heated particles are fed to the bed off from center, the segregation of fine particles and peak of the bed are correspondingly off center and under the area of feed and the greater degree of cooling by air passed through the bed occurs on the areas away from the region where the particles are fed to the bed. Thus the resistance to cooling air flow is greatest in the hotter region of deposition of the particles. This cooling diflerential is magnified by the so-called wall efiect reported in the literature and because the resistance to mass air flow goes up with a rise in temperature of the air. Thus the resistance to air flow goes up in the region of a deposition due to the concerted action of both particle segregation, higher peak, and therefore greater bed depth, and the higher resistance to mass flow of higher temperature air. Where the particles and the cooling air are introduced to the bed is therefore important in determining the location of the highest bed resistance to air flow.

Where, as is often the practice, the hopper system of a lime cooler unit is a cluster of four individual hoppers aligned side-by-side in an overall square assembly, and lime particles are fed to the bed in line with the center region of the four hoppers, the build up of fine particles is in the center of the cooler and the flow of particles spreads radially in all directions therefrom. The thermal gradient, for the reasons set out above, also tends to extend radially outward from the center of the cooler to the exterior wall regions of the cooler, with the highest temperature at the center. The greater resistance to air flow offered by the fine particles segregated-in the central region, and the greater bed depth and tendency toward temperatures in the central region is therefore compensated for according to the present invention.

Difficulties arise in such arrangements in locating the specific points of introduction of cooling air to the quadrants to assure uniform cooling of the particles throughout each level of horizontal cross-section. If properly designed according to the conditions to be confronted in cooling the particles, the uniformity of cooling is attained immediately upon initial installation of the cooler, but in practice this most frequently is not realized. That is, a perfect balance is not always attained in all four hoppers of the cooler, nor in any individual hopper.

BRIEF DESCRIPTION OF INVENTION In view of the foregoing it is an object of the present invention to provide a cooler for heated particles in which a cool air inlet within the bed is adaptable to modification of position to promote establishment of a balanced air flow after installation of the cooler for uniformity of cooling of the particles throughout the bed, and to prevent excessive amounts of air flow through certain sections of the cooler while at the same time other sections do not have enough flow to properly cool the material being charged.

Another object of the invention is to provide such a cooler in which positioning of the cooling air inlet within the bed is along a geometric path of symmetry of dynamic variables whereby the number of variables requiring balance by positioning of the air inlet for uniformity is minimized.

A further object of the invention is to provide a cooler in which the air inlet positioning within the bed is conveniently accomplished externally of the cooler unit.

Another and still further object of the invention is to provide a cooler for heated particles in which the construction is both rugged for reliable operation, yet flexibly adapted to refined tuning matched to optimums of operations under the particular conditions confronted.

In brief, these objectives are attained according to the present invention by providing an arrangement wherein the cooling air inlet within the bed is adjustably positionable on an air inlet duct which in a sense acts as a guide track and whereby air under pressure is supplied to the air port within the bed.

The invention is exemplified in the present disclosure by an arrangement wherein four hoppers are aligned in a cluster of hoppers in opposed relation in an overall square arrangement, and particles to be cooled are fed to the center of the cluster of four hoppers. A specific aspect of the invention is based upon recognition of the symmetry of the pattern of segregation of particles as well as the pattern of cooling in such a cluster of hoppers. By making the cooling air inlet in each of the hoppers movable along a line of symmetry, more particularly a line extending radially from the center of the cooler along a diagonal of the overall square assembly, the complexity of location of the air inlet for balance or optimum of cooling is greatly reduced. By providing adjustability in position in this manner, location of the air inlet in each hopper can be a simple, single in or out movementof the inlet along a radial line from the center of the cooler, thereby also greatly reducing the time required to attain the optimum in cooling uniformity under a given set of operating conditions.

Thus the features of the invention lie in the capability of the cooler construction to be tuned in to operating conditions which typically are not predictable or foreseeable in an optimum sense before actual installation with a source of heated particles to be cooled.

Other features are the ease with which such tuning in is possible, as well as the relatively little time required to effect the balance of operation for the desired uniformity and efficiency of cooling.

A still further feature is the flexible adaptability of the cooler designed according to the principle of the present invention to cooling masses of particles having a wide range of sizes which prior to installation may be unpredictable in their cooling properties.

Other objects and features which are believed to be characteristic of my invention are set forth with particularity in the appended claims. My invention, however, both in organization and manner of construction, together with further objects and features thereof, may be best understood with reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a view in elevation, partially in cross-section of a cooler embodying the improvements of the present invention;

FIG. 2 is a cross-sectional plan view of the cooler taken on line 2-2 of FIG. 1;

FIG. 3 is a somewhat schematic reduced size crosssectional plan view of the cooler of FIGS. 1 and 2 illustrating concentric isothermal lines extending radially outward from the center in like manner in all four hoppers of the cooler;

FIG. 4 is a plan view of a cooler air-inlet assembly incorporated in each of the hoppers of the cooler showing the externally adjustable positioning means of the invention;

FIG. 5 is a partially cut-away, side elevational view of the cooler air-inlet assembly as taken on line 5--5 of FIG. 4;

FIG. 6 is a cross-sectional elevational view of the cooler air-inlet assembly of FIG. 4 as taken on line 6- -6; and

FIG. 7 is a plan view of another embodiment of a cooler hopper arrangement of the present invention in which the inlet is adjustable in position in four directions within a given horizontal plane of the hopper.

DESCRIPTION OF THE INVENTION Referring to the drawings in greater detail, FIG. 1 shows a general arrangement of components of a cooler at the end of an inclined rotary kiln 10 in which limestone or other matter has been calcined or otherwise heat-treated. Burner 11 is representative of one or more burners located at the discharge end of the kiln 10 to supply heat required for calcination or other heat treatment of the charge.

The kiln 10 is inclined downwardly relative to the horizontal so that it discharges its contents by gravity into a cooling chamber 12. Prior to deposition of the kiln product in the cooling bed 13 it is passed through an apertured grate 14 which separates large pieces of kiln coating or masses of lime or clinkers fused together, or foreign matter, from the product of acc'eptable size for treatment in the cooler. Material passing through the grate l4 settles by gravity into a cooling space. The material in the bed 13 moves generally downwardly and continuously into a cluster of four louvered hoppers 17 located in side-by-side relation about the center of the bed. With such an arrangement of a plurality of hoppers rather than a single hopper below the bed, better control of the balance between material and air flow according to the present invention can be'effected as hereafter described in greater detail.

Admission of air to the intermediate region of the bed is accomplished by making each of the hoppers 17 of two interassociated flared hopper sections 18 and 19 with a gap or. louver 38 between. The upper hopper .section 18 has its lower region projecting down into the top of the lower section 19, but spaced from section 19 to form the louver 38. The material passing through the upper hopper section 18 is thus received by what might, in a sense, be considered the main funnel or lower hopper section 19. The material leaving each lower hopper section 19 passes into a lower connected standpipe 20 of long length compared to its cross-sectional dimensions. Each of the hopper standpipes 20 discharges into a separate short hopper 21, with the end of the standpipe being spaced from the top of its respective hopper 21 to allow bleed-off of air into a hood 23 surrounding the ends of all the standpipes 20. The hoppers 21, in turn, discharge the material passed therethrough onto an electro-vibrating feeding mechanism 24 or to mechanical feeder of any other acceptable type, and ultimately to a conveyor belt 25.

Cooling of the material flowing through the hoppers 17 is accomplished by supplying air through the louvers 38, inlet duct 43, and port 39 and ring 44 from a surrounding plenum 30 connected by a duct 32 to a fan 31. Air is drawn by the fan 31 from a main inlet 33 open to the atmosphere by way of a metering orifice 41 in an orifice plate 42. Air is also supplied to the main inlet conduit 33 by way of a conduit 34 connected to the hood 23 at the discharge ends of the standpipes 20. A damper 35 in the conduit 34 regulates the amount of air drawn by the fan 31 from the hood 23.

The cooling air passing upwardly passes through the bed whereupon a portion may be passed upwardly through an exhaust duct 50 leading to a coal pulverizing mill where it may be employed in drying the powdered coal prior to injection of the fuel into the burners, or used to supply high temperature primary air for either gas or oil firing, but a major portion of the air passes directly to the kiln where it is employed as preheated air for combustion.

The apparatus of the cooler thus having been generally described,'the present invention can be understood more clearly by pointing out that the air inlet ports 39 and their associated air baffle-rings 44, as an assembly, each can be moved to different positions within their respective upper hopper sections 18. As may be seen in FIG. 2, air is supplied under pressure from within the plenum 30 to the ports 39 and baffle ring 44 by way of the hopper ducts 43 over which the particles of the bed flow downwardly finally for discharge from the hoppers 21. Thus air is introduced into the interior of the bed and generally in the mid-region of the horizontal cross-section of the hoppers 18. In addition, as pointed out above the air is introduced to the mass of particles between the entrance and exit regions of the hoppers by way of the louvers 38 between the upper hopper sections 18 and lower sections 19. The air gaps presented by the louvers 38 are overlapped to prevent overflow of material passing from the upper sections 18 into the lower sections 19, and are sufficiently large to allow air to be injected into the particles for passage mainly upwardly through the bed but downwardly as well as through the lower funnel and connecting standpipe portions of the hoppers.

FIG. 3 is intended to illustrate how a bed of particles 13, such as in FIG. 1, when flowing downwardly, will divide from the center into all four hoppers 18. Thus each hopper accepts a quadrant of the bed particles. Since at this stage, the bed still functions in the overall, heat dissipation is generally radially outwardly from the center of the bed. This is represented in FIG. 3 by a series of concentric isothermal lines 70 extending from the center outwardly to the exterior of the mass of particles.

An important aspect of the invention now becomes apparent in that it can be seen that on either side of a radial or diagonal line 71 bisecting the hoppers 18, a symmetrical particle size segregation, surface configuration and therefore thermal condition exists. In addition to a thermal symmetry on either side of the line 71 a symmetry also exists in the pattern of distribution of particles according to sizes, and in the depth of bed as determined by surface configuration. That is, in the central region the particles will be of small screen size while on the outer region they are coarser and of a larger screen size, but on either side of the lines 71 the pattern of size distribution will be generally symmetrical, as will the surface of the bed.

Although the symmetry exists on either side of the diagonal line, it should be noted that the thermal or temperature condition from point to point along the diagonal lines are likely to be non-symmetrical, unless some provision is made to accomplish uniformity of temperature along the line in addition to the uniformity on either side of the line. In designing a cooler this asymmetrical thermal condition along the length of the diagonal of the hopper is intended to be overcome by proper location of the air inlet to the bed in each of the hopper regions, but many conditions unforeseeable prior to actual installation of a cooler can arise with any given source of particles to be cooled. That is, if more fines are present in the mass of particles than are originally anticipated, greater blockage or resistance to air flow is present in the center of the hopper, in which instance it would be desirable that the air inlet port 39 be located closer to the central region than to the radially outside regions. Further these variations in size range, and in particle shape, and in initial entrance velocity and direction of particles as they enter the bed all affect the angle of repose and therefore the surface configuration of the bed. Variables tending to effect a loading other than at the center of the cooler are the configuration of the grates, how the particles discharge from the source, and in the case of a kiln, the speeds of the kiln as well as sizes and shapes of the particles and shape of the discharge of the kiln. Thus, depending upon the kiln and its operation upon which the cooler depends for its loading, the cooler might be hotter at the inside under one set of conditions and hotter at the outside under another set of conditions.

According to the present invention, the air inlet assembly of the ports 39 and the air baffles 44 can be adjusted in their position along the length of the line 71 after the initial startup of the cooler based upon the relative temperature as noted by observation or temperature sensor. An approach toward a perfect balance for uniform cooling through-out the bed of particles is thus made possible, thereby overcoming the inability to anticipate and measure all operating variables prior to such installation.

The method and apparatus by which adjustment in position of the central inlet assembly in each of the hoppers can be made is more clearly understandable by reference to FIGS. 4, 5 and 6, wherein it will be seen that the air inlet 39 and baffle ring 44 all are slidable as an assembly mounted on the air inlet duct 43. The duct 43 thus, in a sense, acts as a track for the inlet port and air baffle assembly. The air baffle ring 44 is made up in the form of a ring of angle members. The ring 44 in each hopper is generally in the form of a square in plan except for a comer in the outer comer region which is fore-shortened by a length of angle member 45, making the overall assembly of four air inlet assemblies take on a shape closer to that of an octagon. The hopper assembly is similarly provided a shape approaching circular by providing a comer platform 46 with a depending apron 47 at the corners of the hopper sections 18 corresponding to the corners of the cooler assembly. The refractory above the hopper follows the same shape as the hopper on the sides and at apron 47. Each air inlet assembly thereby also affords a a means for support of the ring 44 on the cap of the inlet port 39 by way of a gusset 48 and air ducts 60 which pass air to ring 44. Thus the air baffle ring acts, in a sense, as a roof for distribution of air introduced thereunder as particles flow downwardly about the ring. In this regard, both the port 39 and the air baffle ring 44 perform dually to provide air into the bed portion flowing downwardly thereover in the hoppers, as well as acting as a battle for the physical flow of particles thereover, thereby retarding the downward draw of material in the same locations. This very desirable combination of effects of retarding material flow in the same locations where air is introduced provides a maximum change in cooling characteristics with a minimum movement of the assembly of the port 39 and ring 44.

By reference to FIG. 6, it can be seen how the air is supplied to the underside of the ring 44 by way of channels 60 extending upwardly from the bottom region of the air inlet port 39 from which they extend. An air cutout opening 61 is provided at the .upper end of the channel 60 just under the air baffle ring 44, thereby pennitting air to be forced upwardly under the ring and about the under part of the baffles from which the air flows around the edges of bafile members and upwardly through the bed. Thus, rather than being merely a concentrated stream of air flowing upwardly from the port 39, the air supplied by way of the ducts 43 to the air inlet assembly goes upwardly through the bed of particles over an appreciable area within each quadrant of the bed at the level of the entrance of particles to the hoppers.

FIGS. and 6 illustrate more clearly how the air is supplied from the plenum 30 to the air duct 43, and enters both the inlet port 39 as well as the upwardly extending air channel 60. The air ducts 43 have a triangular cutout section 57 in opposite sidewalls generally in the mid-region in the length of the duct. If the air inlet port 39, with its hood or flared apron portions 58, extending downwardly on opposite sides of the air duct 43, straddle the duct and enclose the cutout region in the sidewall of the duct, the air passing into the duct enters and is emitted from the hood 58 of the air inlet port 39 as well as passing upwardly through the channels 60 and exit into the bed of particles flowing thereover.

It is possible to make the adjustability in position in the straddling air inlet assembly flexible over an appreciable length of the duct :13. The duct 43 in a sense might be considered a tunnel leading to the inlet port 39. The duct might have a dimension generally in the order of 4 inches wide and inches high. With duct dimensions of this order, it has been found that in most instances a plus or minus 2 to 4 inches in either direction is all that is required to attain the proper location of the air inlet assembly for desired balance of cooling in the bed. It will be understood, however, that these dimensions are given merely by way of example and not by way of limitation since a wide range of adjustment of the air inlet port assemblies is possible as determined by proportioning the size of the cutout portions 57 and the straddling hoods formed by the apron portions 58 of the inlets 39.

FIGS. 4 and 5 illustrate in more detail the manner in which adjustability in position is made possible in the present arrangement. The air inlet port and baffle assembly, as indicated above, straddles the air inlet duct 43, and retaining brackets 51 and 56 at opposite ends of the straddled portion of the assembly, extend under the duct and act both as retainers and guide members for sliding movement of the. assembly along the length of the duct 43. The retaining bracket member 51 is an angle member to which an adjusting rod 50 is connected by way of a pair of spaced collars 52 on opposite sides of the dependent portion of the angle member 51. The collars 52 are suitably secured to the adjustment rod such as by welding them thereto but have sufficient play therebetween to allow rotation of the rod while still engaging the member for a push and pull relationship of the entire assembly. Each rod 50 is of length sufficient that it can extend through openings in the bottom edge of the upper hopper section 18 with which it is associated and the upper edge portion of the bottom hopper section 19 and through a fixedly mounted internally threaded collar 53 for reach just beyond the wall of the plenum 30. Adjustable positioning of the air inlet port and'baffle assembly can be suitably accomplished over thelength of the inlet duct 43 by threading the ad justment rod through the stationarily positioned collar 53 with the aid 'of a wrench for engagement of a hexagon shaped head 54 fixed to the end of the rod 50.

In prior coolers, not having provision for such an adjustment, it has been found that the particles might be extremely hot on the inside region of the bed, while the outside wall is needlessly cooled to ambient air temperatures. At other times, the complete opposite may occur where, for reasons set out above, the inside may be cold and the outside may be extremely hot. In no case, however, would both the inside and the outside be hot if the cooler is designed exactly for the conditions confronted. In practice the degree of accuracy of the initial adjustment can be determined by merely feeling the particles. At times the particles may be so hot that they need not be touched because the radiated heat can be felt by placing ones hand near the particles or by use of a temperature sensor such as a thermocouple or thermometer; whereas the opposite side of the bed might be felt and found to be cold. The high temperatures experienced might be anywhere in the region of 200 to 400 F. Under balanced conditions, however, the particles can all be within 50' F. or less of ambient air temperature. In an assembly of hoppers exemplifying the invention herein, two hoppers might be typically cold, and of the remaining .two hoppers, one or both might be cold on one side and hot on the other. The cooler side of the cooler unit can be, for example, cooled substantially more than required. Thus, that side is cooled needlessly to a lower temperature than necessary.

Since in the application of such coolers to kilns, only that amount of air can be blown to cool which can subsequently be used for combustion, and since cooling with minimum quantities of air reduces power requirements, it is necessary to have uniformly cooled particles for maximum recuperation of heat and minimum fan power consumption.

As pointed out above, a feature of the invention is the repositionability of the air inlet assembly in a desired position in the hopper to attain an optimum airmaterial balance. This can be accomplished easily either with the adjustment screw described or by use of an hydraulic or pneumatic cylinder to position assembly 39-44. The adjustment is made as determined by the temperature discharge profile sensed by any of a number of means including, a thermocouple or thermometer, or by manual sensing as explained above.

Although the invention is exemplified by adjustment of the air inlet assembly along a diagonal line extending across the hopper as explained above, it is contemplated that the invention not be limited to such an arrangement only in that it is possible to arrange for repositioning an air inlet in more than one linear direction in a given plane of a hopper. That is the air inlet such as that shown in FIG. 6 can be made repositionable laterally within a hopper as well as the length of the duct. That is, the air inlet port 39 can be adjustably positioned along the duct 43 by way of an adjustment rod 80 while the opposite end of the duct 43 can be made adjustable in position laterally by way of an adjustment rod 81. Altemately, the duct 43 might be made laterally positionable by providing horizontal slots in the wall sections through which the rod 50 of FIGS. 4 to 6 can extend and by providing a pivot for the duct at the cooler center to make it possible to move the port 39 and baffle 44 assembly both longitudinally along the duct 43 and laterally of the hopper by way of the rod 50. Thus, the position of the air inlet port 39 can be made adjustable within desired limits both longitudinally and laterally of the original position of the duct across the hopper with which it is associated.

In view of the foregoing, while the invention has been described in considerable detail with regard to the illustrated preferred embodiment, it will be understood that my invention is not limited specifically to the particular arrangement shown and described, and accordingly by the appended claims, all adaptions, modifications and arrangements thereof are contemplated which fall within the true spirit and scope of the invention.

I claim:

1. Apparatus for passing a gas through a mass of particles comprising means for containing a mass of said particles, means for supplying particles to the upper region of said mass,

means for withdrawing particles from a lower region of said mass,

gas inlet means interior of said mass intermediate the upper and lower regions of said mass,

means comprising a duct providing a gas passage connected to said inlet means,

positive pressure means for introducing gas under pressure to said duct means and inlet means, and;

means for adjustably positioning said gas inlet means in a traverse direction within said mass for establishment of desired patterns of gas flow through said particles.

2. Apparatus according to claim I in which each of the gas inlet means comprises,

a hood with an air exit port movable to different positions along the length of the duct with which it is associated.

3. Apparatus for cooling hot particles comprising means for containing a bed of said particles, means for supplying heated particles to the upper region of said bed,

means for withdrawing cooled particles from the lower region of said bed,

air inlet means interior of said bed, positive pressure means for introducing air under pressure to said air inlet means, and

means for adjustably positioning said air inlet means laterally within said bed for establishment of desired patterns of air flow and cooling of particles within said bed.

4. Apparatus for passing a gas through a mass of particles comprising means for containing a mass of said particles, means for supplying particles to the upper region of said mass,

means for withdrawing particles from a lower region of said mass, gas inlet means interior of said mass intermediate the upper and lower regions of said mass,

positive pressure means for introducing said gas under pressure to said inlet, and;

means adjustable external of said cooling apparatus connected to said gas inlet positioning means for selecting an operating position of said gas inlet means within said bed.

5. Apparatus for cooling hot particles comprising means for containing a bed of said particles, 7 means for supplying heated particles to the central region of the upper surface of said bed,

a plurality of hoppers below said surface and spaced about a vertical center axis of said bed for receiving the particles of said bed,

means associated with each of said hoppers for receiving the discharge of said hopper,

an air inlet means interiorly of said bed in the region of the entrance of each of said hoppers,

positive pressure means for introducing air under pressure to each of said air inlet means, and adjustment means for positioning the air inlet means of each of said hoppers in connected relation with said positive pressure means along a line extending radially from the central axis of said bed.

6. Apparatus according to claim 5 in which the means for positioning the air inlet means comprises air passage means permitting positioning of the air inlet of each of said hoppers along a radial line bisecting the horizontal cross-sectional area of its respective hopper at the level of the air inlet means.

7. Apparatus for cooling hot particles comprising means for containing a bed of said particles,

means for supplying heated particles to the upper surface of said bed,

a plurality of hoppers below said surface and spaced about a vertical center axis of said bed for receiving the particles of said bed,

each of said hoppers having an opening for discharge of particles therefrom,

means associated with the discharge opening of each of said hoppers for receiving the discharge of said pp means for supplying cooling air below the central region of said bed,

air ducts extending radially outward from said central region each into a respective one of said hop- P along a line bisecting the horizontal cross-sectional area of the hopper into which it extends.

9. Particle cooling apparatus according to claim 8 in which the said hoppers and ducts are spaced equal angular distances apart about said central region'- 10. Particle cooling apparatus according to claim 9 in which thehoppers and ducts are four in number oriented 90 apart about said central region.

11. Particle cooling apparatus according to claim 7 in which each of the air outlet means comprises an inlet hood with an air exit port movable to different positions along the length of the duct with which it is associated.

12. Particle cooling apparatus according to claim 11 in which each air inlet hood is disposed above its respective duct and extends on opposite sides of the duct in air flow connection with air openings in said duct sides.

l3. Particle cooling apparatus according to claim 12 in which each air outlet means comprises an air outlet assembly including an air inlet hood and an overlying air releasing baffle ring disposed above and about said port, said air baffle ring having an open air passage thereunder for release of air into said bed about said 3 outlet hood.

14. Apparatus for cooling hot particles comprising means for containing a bed of said particles,

means for supplying heated particles to the upper region of said bed, means for withdrawing cooled particles from the lower region of said bed,

means for supplying cooling air below the central region of said bed,

air ducts extending outward from said central region,

air inlet means associated with each of said ducts between the center and edge of said bed for release of air from the duct to within said bed, each said air inlet means comprising an air inlet as- 1 sembly including a hood having an inlet port and a baffle ring, extending in a region about said port, said airbaffle ring having an underlying open air passage for release of air in'tosaid bed.

15L Particle cooling apparatus according to claim 14 in which the overlying baffle ring is connected-by at least one air passage means extending laterally upward from an air connection with itsrespective' duct.

16. Particle cooling apparatus according to claim 14 wherein the air bafile ring is connected by two air passage means extending laterally upward from air connections with opposite sides of said duct.v

l7. Particle cooling apparatus according to claim 14 including means for positioning each air inlet means to different positions along the length of the duct with which it is associated.

l8. Particle cooling apparatus according to claim 14 wherein each air inlet means is moveable to different locations along the lengthof the duct with which it is associated and means is provided for positioning said air inlet means accessible externally of said cooling ap- 

1. Apparatus for passing a gas through a mass of particles comprising means for containing a mass of said particles, means for supplying particles to the upper region of said mass, means for withdrawing particles from a lower region of said mass, gas inlet means interior of said mass intermediate the upper and lower regions of said mass, means comprising a duct providing a gas passage connected to said inlet means, positive pressure means for introducing gas under pressure to said duct means and inlet means, and; means for adjustably positioning said gas inlet means in a traverse direction within said mass for establishment of desired patterns of gas flow through said particles.
 2. Apparatus according to claim 1 in which each of the gas inlet means comprises, a hood with an air exit port movable to different positions along the length of the duct with which it is associated.
 3. Apparatus for cooling hot particles comprising means for containing a bed of said particles, means for supplying heated particles to the upper region of said bed, means for withdrawing cooled particles from the lower region of said bed, air inlet means interior of said bed, positive pressure means for introducing air under pressure to said air inlet means, and means for adjustably positioning said air inlet means laterally within said bed for establishment of desired patterns of air flow And cooling of particles within said bed.
 4. Apparatus for passing a gas through a mass of particles comprising means for containing a mass of said particles, means for supplying particles to the upper region of said mass, means for withdrawing particles from a lower region of said mass, gas inlet means interior of said mass intermediate the upper and lower regions of said mass, positive pressure means for introducing said gas under pressure to said inlet, and; means adjustable external of said cooling apparatus connected to said gas inlet positioning means for selecting an operating position of said gas inlet means within said bed.
 5. Apparatus for cooling hot particles comprising means for containing a bed of said particles, means for supplying heated particles to the central region of the upper surface of said bed, a plurality of hoppers below said surface and spaced about a vertical center axis of said bed for receiving the particles of said bed, means associated with each of said hoppers for receiving the discharge of said hopper, an air inlet means interiorly of said bed in the region of the entrance of each of said hoppers, positive pressure means for introducing air under pressure to each of said air inlet means, and adjustment means for positioning the air inlet means of each of said hoppers in connected relation with said positive pressure means along a line extending radially from the central axis of said bed.
 6. Apparatus according to claim 5 in which the means for positioning the air inlet means comprises air passage means permitting positioning of the air inlet of each of said hoppers along a radial line bisecting the horizontal cross-sectional area of its respective hopper at the level of the air inlet means.
 7. Apparatus for cooling hot particles comprising means for containing a bed of said particles, means for supplying heated particles to the upper surface of said bed, a plurality of hoppers below said surface and spaced about a vertical center axis of said bed for receiving the particles of said bed, each of said hoppers having an opening for discharge of particles therefrom, means associated with the discharge opening of each of said hoppers for receiving the discharge of said hopper, means for supplying cooling air below the central region of said bed, air ducts extending radially outward from said central region each into a respective one of said hoppers, air inlet means disposed in air communication with each of said ducts generally over the discharge opening of each of said hoppers between the center and edge of said bed for release of air from the duct to within said bed.
 8. Particle cooling apparatus according to claim 7 in which each of said ducts is oriented so that it extends along a line bisecting the horizontal cross-sectional area of the hopper into which it extends.
 9. Particle cooling apparatus according to claim 8 in which the said hoppers and ducts are spaced equal angular distances apart about said central region.
 10. Particle cooling apparatus according to claim 9 in which the hoppers and ducts are four in number oriented 90* apart about said central region.
 11. Particle cooling apparatus according to claim 7 in which each of the air outlet means comprises an inlet hood with an air exit port movable to different positions along the length of the duct with which it is associated.
 12. Particle cooling apparatus according to claim 11 in which each air inlet hood is disposed above its respective duct and extends on opposite sides of the duct in air flow connection with air openings in said duct sides.
 13. Particle cooling apparatus according to claim 12 in which each air outlet means comprises an air outlet assembly including an air inlet hood and an overlying air releasing baffle ring disposed above and about said port, said air baffle ring having an open air passage thereunder for release of air into said bed about said outlEt hood.
 14. Apparatus for cooling hot particles comprising means for containing a bed of said particles, means for supplying heated particles to the upper region of said bed, means for withdrawing cooled particles from the lower region of said bed, means for supplying cooling air below the central region of said bed, air ducts extending outward from said central region, air inlet means associated with each of said ducts between the center and edge of said bed for release of air from the duct to within said bed, each said air inlet means comprising an air inlet assembly including a hood having an inlet port and a baffle ring, extending in a region about said port, said air baffle ring having an underlying open air passage for release of air into said bed.
 15. Particle cooling apparatus according to claim 14 in which the overlying baffle ring is connected by at least one air passage means extending laterally upward from an air connection with its respective duct.
 16. Particle cooling apparatus according to claim 14 wherein the air baffle ring is connected by two air passage means extending laterally upward from air connections with opposite sides of said duct.
 17. Particle cooling apparatus according to claim 14 including means for positioning each air inlet means to different positions along the length of the duct with which it is associated.
 18. Particle cooling apparatus according to claim 14 wherein each air inlet means is moveable to different locations along the length of the duct with which it is associated and means is provided for positioning said air inlet means accessible externally of said cooling apparatus.
 19. Particle cooling apparatus according to claim 18 in which the externally accessible positioning means comprises a rod connected to said air inlet means.
 20. Particle cooling apparatus according to claim 19 in which the positioning of said air inlet means is effected by rotational adjustment of said connected rod. 